The invention relates in general to weapon systems and in particular to a retention device for positioning propellant and/or ammunition in guns.
The problem of how to hold munitions in an open cannon chamber has existed for as long as cannons have been used. A common method is to de-elevate the cannon to a horizontal position between firings. This method drastically reduces the number of rounds fired per minute because of the time needed to reposition the cannon for firing. Another method used to hold propellant in an elevated chamber is the Swiss notch. The Swiss notch is basically a notch cut into the chamber of the cannon at the six o'clock position. The notch is designed so that propellant bags or charge modules will catch on the notch if they begin to fall out of the chamber due to gravity. The Swiss notch is only somewhat effective because it is totally dependent on the drop angle, weight, and profile of the propellant bag or module to fall uncontrolled into the notch. At higher angles, the propellant bag or module may not fall into the notch. In addition, experience has shown that the Swiss notch is not a foolproof method to keep the propellant bag or charge modules from falling out of the chamber at any elevated angle. Further, the combustion debris may fill the notch and render it useless.
In a breech-loaded cannon, it is most efficient to load propellant bags or charge modules using a device such as an automatic loader. Typically, the propellant bags or modules are loaded with the cannon muzzle at an elevated angle. However, upon withdrawal of the auto-loader ram, the propellant can fall out of the chamber due to the elevated muzzle.